1. Field of the Invention
The present invention relates to lighting systems, and more particularly to the control of images in a lighting system that includes multiparameter lights having an image projection lighting parameter.
2. Description of the Related Art
Lighting systems are formed typically by interconnecting many light fixtures by a communications system and providing for operator control from a central controller. Such lighting systems may contain multiparameter light fixtures, which illustratively are light fixtures having individually remotely adjustable parameters such as beam size, color, shape, angle, and other light characteristics. Multiparameter light fixtures are widely used in lighting industry because they facilitate significant reductions in overall lighting system size and permit dynamic changes to the final lighting effect. Applications and events in which multiparameter light fixtures are used to great advantage include showrooms, television lighting, stage lighting, architectural lighting, live concerts, and theme parks. Illustrative multiparameter light devices are disclosed in the product brochure entitled “The High End Systems Product Line 2001” and are available from High End Systems, Inc. of Austin, Tex.
To program the multiparameter lights, the operator inputs to a keyboard of the lighting central controller (or central controller) to send commands over the communications system to vary the parameters of the lights. When the operator of the lighting central controller has set the parameters of the multiparameter lights to produce the desired effect, the operator has produced a “scene.” Each scene with its corresponding parameter values is then stored in the memory of the central controller for later recall by the operator or as an automated recall. As many as 100 or more scenes may be put together to make a “show”.
Prior to the advent of relatively small commercial digital controllers, remote control of light fixtures from a central controller was done with either a high voltage or low voltage current; see, e.g., U.S. Pat. No. 3,706,914, issued Dec. 19, 1972 to Van Buren, and U.S. Pat. No. 3,898,643, issued Aug. 5, 1975 to Ettlinger. With the widespread use of digital computers, digital serial communications has been adopted as a way to achieve remote control; see, e.g., U.S. Pat. No. 4,095,139, issued Jun. 13, 1978 to Symonds et al., and U.S. Pat. No. 4,697,227, issued Sep. 29, 1987 to Callahan.
A multiparameter light has several parameters that can be adjusted by remote control. A central controller is used in combination with a communication system to remotely control the multiparameter lights. Typically, the central controller is programmed in advance by an operator to control the lighting system. An example of a widely used central controller for multiparameter lights is the Whole Hog II, which is manufactured by Flying Pig Systems of 53 Northfield Road, London W13 9SY, and disclosed in a product brochure entitled “Whole Hog II, Lighting Control Workstation” available from Flying Pig Systems. Examples of some of the parameters that can be remotely controlled are position, color, pattern, iris, dimming, and shutter to name a few. Multiparameter lights can have over 12 parameters that are controlled by the central controller. Each multiparameter light can be set to respond to a specific address in the protocol used over the digital serial communication system. Typically the multiparameter light is first addressed by an operator of the central controller and next a parameter of the multiparameter light is adjusted from the central controller by the operator.
Multiparameter lights typically use metal or glass masks to act as a slide for the projection of an image. The metal or glass masks made for the lights are referred to in the industry as “gobos”. Typically a gobo is placed into the light path within the housing of the multiparameter light by a motor or other type of actuator. The actuator turns a wheel referred to as a “gobo wheel” that contains multiple apertures, and each aperture contains a gobo that can be placed into the light path. The actuator is controlled by the electronic system of the multiparameter light in response to commands received over the communication system from the central controller. Each gobo aperture in some multiparameter lights can rotate the gobo itself in the path of the light. Additional description of gobo technology can be found in my U.S. Pat. No. 5,402,326 entitled “Gobo holder for a lighting system,” which issued Mar. 28, 1995.
A type of advanced multiparameter light fixture which is referred to herein as an image projection lighting device (“IPLD”) uses a light valve to project images onto a stage or other projection surface. A light valve, which is also known as an image gate, is a device such as a digital micro-mirror (“DMD”) or a liquid crystal display (“LCD”) that forms the image that is projected. Other types of light valves are LCOS and MEMS. U.S. Pat. No. 6,057,958, issued May 2, 2000 to Hunt, discloses a pixel based gobo record control format for storing gobo images in the memory of a light fixture. The gobo images can be recalled and modified from commands sent by the control console. U.S. Pat. No. 5,829,868, issued Nov. 3, 1998 to Hutton, discloses storing video frames as cues locally in a lamp, and supplying them as directed to the image gate to produce animated and real-time imaging. A single frame can also be manipulated through processing to produce multiple variations. Alternatively, a video communication link can be employed to supply continuous video from a remote source.
U.S. Pat. No. 5,828,485, issued Oct. 27, 1998 to Hewlett, discloses the use of a camera with a DMD equipped lighting fixture for the purpose of following the shape of the performer and illuminating the performer using a shape that adaptively follows the performer's image. The camera acquiring the image preferably is located at the lamp illuminating the scene in order to avoid parallax. The image can be manually investigated at each lamp or downloaded to some central processor for this purpose. This results in a shadowless follow spot.
Since multiparameter light fixtures of the type that project an image using a gobo typically use gobo wheels to place various gobos into the light path, and since a gobo wheel typically has several positions, it is common for the central controller to display to the operator a position number of the gobo wheel on some type of visual display device. The visual display device may be a CRT monitor or LCD touch screen or the like. The gobo parameter selectively varied with the use of the gobo wheel of the prior art typically is referred to as the gobo parameter or gobo position parameter.
FIG. 1 shows a central controller 110 and multiparameter lighting devices 120 and 122 of the gobo type. A display device 150, a keyboard 140 for entering control commands, and control input devices 145 are shown as part of the central controller 110. A communications line 116 interconnects the central controller to the multiparameter lighting device 120. Communications line 121 is connected between light 120 and light 122 so that light 122 can also receive communications from the central controller 110. Only two multiparameter lighting devices are shown in FIG. 1 although it is known in the art to interconnect 30 or more devices for larger shows.
Multiparameter lights 120 and 122 have several parameters that can be adjusted from the central controller 110. For simplification, lights 120 and 122 are considered the same fixture type and include the following variable parameters: pan, tilt, color, gobo, gobo rotate, and intensity. The operator of the central controller sets the correct fixture type within the central controller software, and sets up the central controller to control the two lights 120 and 122.
FIG. 2 shows a condensed version of a display screen 200 (analogous to the display device screen 150 of FIG. 1) for scene one. With the display screen 200 the parameters of the lights 120 and 122 may be varied. The operator may move a cursor on the display screen 200 using, for example, any suitable input device (not shown) to select the line of the parameter of the specific fixture to be varied. The operator may also use one of the input devices 145 or keyboard 140 to vary the selected parameter. When the operator has adjusted all of the desired parameters of the lights, the operator has created a scene. Next the operator may advance the screen to the next scene and adjust the parameters. Once the desired number of scenes have been created, the operator may recall the scenes during a live performance or show to obtain a pleasing visual effect.
The parameter information shown on the visual display screen 200 is condensed for simplicity. Typically, a display would include many more fixtures of different fixture types. It is also known to display the duration time of a scene and any crossfade time between scenes. For example the time that a first scene fades into a second scene.
A typical example of bow the visual display of the gobo wheel position number may be used by the operator during advanced programming of the central controller is as follows. The operator first selects the operating address of one of the multiparameter light fixtures to modify a parameter. Next the operator modifies the chosen parameter. For example, the operator sees on the display device screen a list of parameters that can be selected for modification of the particular light chosen, and then selects a parameter to modify such as “color wheel.” If the color wheel happens to have ten apertures to choose from, the operator may choose aperture 3 which happens to be green. The operator may continue the programming by addressing other multiparameter lights and change the color parameter to aperture 3 or even other apertures. The operator typically sees the aperture number on the visual display device screen, but might instead see the colors of the apertures instead of just numbered apertures if the central controller has in its memory the “fixture type” for the particular light being controlled. Central controllers like the Whole Hog II are capable of prestoring “fixture types” in the controllers memory. A fixture type is all the particular attributes of a specific manufacturers brand or model of multiparameter light.
Unfortunately, one problem with displaying aperture colors from information pre-stored at the central controller arises when, for example, a service technician removes the green color filter of aperture 3 of a specific fixture type and replaces it with a custom color. Now unless the fixture type information is updated at the central controller, the visual display device screen at the central controller will still show green for aperture 3 instead of the custom color.
Gobo wheel aperture selection in the prior art has problems similar to those involved in color wheel aperture selection as described above. The gobos that are mounted to the gobo wheel apertures of a particular fixture type do not change unless a service technician exchanges a gobo from one of the apertures with a custom gobo that may have been specified by the operator or show lighting designer. The gobo pattern images of the prior art cannot be changed to different patterns electronically like images can be changed when IPLD lighting devices change images using light valves.
The use of IPLDs in a lighting system avoids some of the problems with the types of multiparameter lights that use color wheels and gobos but introduces new problems. Unlike multiparameter lights that have a fixed number of gobos that the operator can easily choose from when programming an IPLD from a central controller, IPLD lighting devices are capable of being used to project a wide range of different images, some of which may be pre-stored internally but some of which may not be pre-stored. The techniques used by conventional central controllers to program multiparameter lights do not work as effectively as might be desired for programming IPLD lighting devices. Moreover, while the type of light fixture that provides a shadowless follow spot function and other types of light fixture that similarly store images internally for projection have value in the lighting industry, these types of light fixtures and/or the lighting systems in which they operate all limit the operator of the lighting system to carrying out image projection operations on the basis of individual light fixtures. Moreover, having to store images at the light fixture is very limiting to the user of the device, since the operator must upload images to the light fixture from a computer before placing the light fixture into service.
An example of a type of stage lighting projection system that uses a double mirror orbital head and a video projector is disclosed in International Publication No. WO 02/21832, published Mar. 14, 2002. The system uses an image processor to correct for the expected rotation and other distortion effects that would otherwise result from an image passing through the double mirror head. Image data from an image store is provided to the image processor along a video link. Orientation of the double mirror head is effected by a signal from a computer controller to the head over a DMX link. The controller then directs a DMX processing signal to the image processor, which processes the image data so as to introduce a correction for the expected rotation and other distortion effects. The controller also directs a DMX signal to the head to effect a desired focus and zoom. The processed image data from the image processor then is provided via a video link to the image projector, so that the image is projected with desired orientation, focus, zoom and appearance. A similar system known as the Catalyst™ system is available from High End Systems, Inc. of Austin, Tex., and is described in the Catalyst system brochure. While the Catalyst system has met with some success, use of the image store is cumbersome and generally unfamiliar to many operators of lighting systems, and increases the setup complexity of the lighting system.
A multiprojector system in which an image is projected by plural projectors is disclosed in U.S. Pat. No. 5,988,817. The multiprojector system uses a number of “image-inputting” devices, one for each image that is to be projected by the projectors. The images to be projected are furnished to a multiple video processor, from which they are directed to the projectors. Where an image is to be enlarged and projected by two, four or more projectors, the image is enlarged in the multiple video processor before being supplied to the projectors. Disadvantageously, the use of multiple image-inputting devices and a multiple video processor is generally unfamiliar to many operators of lighting systems, and increases the setup complexity of the lighting system.